#include <stdio.h>
int main() {
    // 5行hello world
    printf("hello world\n");
    printf("hello world\n");
    printf("hello world\n");
    printf("hello world\n");
    printf("hello world\n");
    // 2行goodbye world
    printf("goodbye world\n");
    printf("goodbye world\n");
    return 0;
}
